The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 2001
Filed:
Mar. 04, 1999
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
A (meth)acrylic acid polymer is obtained by conducting a polymerization reaction using 60 mol % or more of a hydrophilic monomer containing (meth)acrylic acid and a combination of at least one kind of persulfate salts and at least one kind of bisulfite salts as an initiator series under conditions that a pH is smaller than 5 and a degree of neutralization is smaller than 40 mol %, in such a manner that a solid concentration when the polymerization reaction ends is 40% or higher. The resulting polymer has a weight average molecular weight ranging from 3,000 to 15,000, a sulfonic acid group at an end terminal, and an anti-gelling ability Q-value smaller than 2.0, where the anti-gelling ability Q-value is defined as: